type: JSO4 thread sizes M3,M3.5 ,M4,M5. Self Clinching Standoffs provide a strong torque resistant captivated female thread in a spacer configuration for thin panel applications. Available in Steel, Stainless Steel and Aluminum .As minimal surface finishing is required after installation, this fastener installs fully flush from the back of the panel. The hexagon head provides excellent torque out and push out resistance.